Running AEM forms in maintenance mode

Maintenance mode is useful when performing tasks such as
patching a DSC, upgrading AEM forms, or applying a service pack.

Avoid invoking any processes while the server is in maintenance
mode. This is what happens if a process is invoked while the server
is in maintenance mode:

If the process is long-lived, it is added to the job
database, but is not started. When you exit maintenance mode, AEM
forms processes the long-lived jobs in its queue, even if the server
was restarted while in maintenance mode.